Roy Moore is expected to announce his candidacy (or his non-candidacy, but I'm betting he will run) for one of the U.S. Senate seats from Alabama today.
He ran against Democratic candidate Doug Jones---and lost---in 2016. If he wins the Republican Primary next March 3rd, and becomes the GOP nominee, it will be a rematch.
Meanwhile The Alabama U.S Senator who is not up for reelection next year says former U.S. Senator Jeff Session, has not decided if he will run for the seat:
"Sessions I don't think has ruled it out," Sen. Richard C. Shelby, R-Ala., told reporters. "I've talked to him about it. I think if he ran he would be a formidable candidate, formidable. I've not encouraged him to run, but he's a friend, and if he ran I think he'd probably clear the field."(From a Stanford Advocate story,)